(a) Field of the Invention
The present invention relates generally to receiving and recording digital packet data. More particularly, it relates to a method and apparatus for receiving broadcast entertainment-type data, such as the packetized digital video, audio, and information data signals transmitted in a direct broadcast satellite (DBS) or digital video broadcast (DVB) system, and for effectively recording the received data on a device such as a digital VHS (DVHS) unit. The recording process may include the insertion of locally generated or locally derived data into the recorded data stream.
(b) Description of Related Art
Conventional communications systems include a receiver for receiving and processing transmitted waveforms. One type of receiver is part of a "wireless digital television" system known commercially by the tradename DSS.RTM.. The DSS system, which is utilized by the DIRECTV.RTM. broadcast service, allows consumers to receive directly in their homes over 175 television channels broadcast from a pair of powerful satellites. The receiver includes a small 18-inch satellite dish connected by a cable to an integrated receiver/decoder unit (IRD). The satellite dish is aimed toward the satellites, and the IRD is connected to the user's television in a similar fashion to a conventional cable-TV decoder.
On the transmission side, video, audio, and related information data signals are digitally encoded into a packetized data stream using a number of algorithms, including convolutional error correction. The encoded data stream is then punctured to reduce bandwidth requirements, modulated to Ku-band frequency, transmitted to the satellite, and relayed from the satellite to the 18-inch satellite dish. The satellite dish shifts the Ku-band signal down to an L-band signal which is transmitted through the cable to the IRD.
In the IRD, front-end circuitry receives the L-band signal and converts it to the original digital data stream of video, audio, and related information signals. The digital data stream is fed to video/audio decoder circuits which perform the main video/audio processing functions such as demultiplexing and decompression. A micro-controller controls the overall operation of the IRD, including the selection of parameters, the set-up and control of components, channel selection, viewer access to different programming packages, blocking certain channels, and many other functions. The compression and decompression of packetized video and audio signals may be accomplished according to the Motion Picture Expert Group (MPEG) standard for performing digital video/audio compression. Thus, the IRD unit typically includes an MPEG-1 or MPEG-2 video/audio decoder in order to decompress the received compressed video/audio.
In general, digital video and audio signals can be transported, processed, and recorded with a high degree of quality. In order to take better advantage of the high quality associated with digital video/audio, digitally-based peripheral devices, such as digital video cassette recorders (DVCR's) and digital video disks (DVD's), have been developed to receive and process video/audio in a digital format. The present invention relates to a method and apparatus for receiving broadcast entertainment-type data, such as packetized digital video, audio, data, and control signals received in a direct broadcast satellite (DBS) system, and for effectively recording the received data on a device such as a digital VHS (DVHS) unit.